1. Technical Field
The disclosure relates to a hybrid vehicle, and particularly, to a hybrid vehicle including an engine, a motor, and a battery.
2. Description of the Related Art
In the related art, as an internal combustion engine system, there is suggested an internal combustion engine system which includes an internal combustion engine, and a particulate matter (PM) removing device provided in an exhaust passage of the internal combustion engine, and in which, when the cooling water temperature of the internal combustion engine is lower than a reference temperature and the number of PM particles in exhaust gas after passing through the PM removing device is more than a reference particle number, an operation point (engine rotational speed and engine load) of the internal combustion engine is changed so that the PM particle number in the exhaust gas from the internal combustion engine decreases (for example, refer to Japanese Patent Application Publication No. 2012-219746 (JP 2012-219746 A). In this system, a PM particle number in exhaust gas discharged out of the system is reduced by the above-described control.
Among hybrid vehicles which include an internal combustion engine and an electric motor for vehicle driving and a battery that exchanges power with this electric motor and which drive the engine while the engine is intermittently operated, there is a hybrid vehicle that executes the following first control or second control according to a cooling water temperature (starting point water temperature) at the time of the start of operation of the internal combustion engine. In the first control, when the starting point water temperature is equal to or lower than a first predetermined temperature, the output of the internal combustion engine is limited to a first predetermined output or lower, and a catalyst of an exhaust gas control apparatus of the internal combustion engine is warmed up until the cooling water temperature becomes higher than the first predetermined temperature. In the second control, when the starting point water temperature is higher than the first predetermined temperature and is equal to or lower than the second predetermined temperature, the output of the internal combustion engine is limited to a second predetermined output or lower that is greater than the first predetermined output and an increase in the PM particle number is suppressed until the cooling water temperature becomes higher than the second predetermined temperature. In this case, at the execution of the first control and the second control, when a rise in the cooling water temperature is relatively gentle, the execution times of the first control and the second control may become relatively long. If the execution times of the first control and the second control become relatively long, the time during which the output from the motor and eventually the discharge power from the battery are apt to be relatively great may continue for a relatively long time, and the power storage proportion of the battery may drop relatively greatly. For this reason, it is preferable to prevent the execution times of the first control and the second control from becoming relatively long.